Optical disk drive with adaptive compensator

Abstract

An optical disk drive for accessing data stored on a compact disc has a housing, a sled sliding inside the housing, a driving device for driving the sled, an actuator installed on the sled, a servo device for providing a push force to drive the actuator, a control circuitry for controlling operations of the optical disk drive, an adaptive compensator, and an error signal generation circuit. The actuator can move within a predetermined range on the sled, wherein the predetermined range includes a linear region and a non-linear region. It is desirable to keep the actuator within the linear region of the predetermined range. For this, an adaptive compensator is used to provide a supplementary force to the sled when the actuator is near the non-linear region.

What is claimed is:  
     
       1. An optical disk drive for accessing data stored on an optical disc, comprising: 
       a sled;  
       a driving device for driving the sled;  
       an actuator on the sled and moveable within a predetermined range on the sled;  
       a servo device for providing a push force to drive the actuator wherein when the actuator moves within a linear region of the predetermined range, a displacement of the actuator on the sled has a linear relationship with the push force; and when the actuator moves within a non-linear region of the predetermined range, the displacement of the actuator on the sled has a non-linear relationship with the push force;  
       a control circuitry for controlling the optical disk drive, the control circuitry comprising a compensation device for making the driving device to provide a driving force to drive the sled; and  
       an adaptive compensator for making the driving device provide a supplementary force to the sled so as to drive the actuator away from the non-linear region;  
       wherein the adaptive compensator makes the driving device provide the supplementary force to push the sled according to an error signal so as to drive the actuator away from the non-linear region.  
     
     
       2. The optical disk drive of  claim 1 , wherein the adaptive compensator makes the driving device provide the supplementary force to push the sled when a magnitude of the error signal is greater than a predetermined value so as to drive the actuator away from the non-linear region. 
     
     
       3. A method for controlling an optical disk drive to access data stored in an optical disc, the optical disk drive comprising: 
       a sled;  
       a driving device for driving the sled;  
       an actuator installed on the sled and moveable within a predetermined range on the sled; and  
       a compensation device for making the driving device provide a driving force to drive the sled;  
       the method comprising:  
       detecting if the actuator is near to a non-linear region of the predetermined range; and  
       providing a supplementary force in addition to the driving force to drive the sled so as to drive the actuator away from the non-linear region of the predetermined range if the actuator is near the non-linear region of the predetermined range.  
     
     
       4. The method of  claim 3  further comprising the steps of: 
       generating an error signal according to a position relationship between the actuator and the compact disc; and  
       determining that the actuator is near the non-linear region of the predetermined range if the magnitude of the error signal is greater than a predetermined value.  
     
     
       5. A method for controlling an optical disk drive to access data stored in an optical disc, the optical disk drive comprising: 
       a sled;  
       a driving device for driving the sled;  
       an actuator installed on the sled and moveable within a predetermined range on the sled;  
       a compensation device for making the driving device provide a driving force to drive the sled; and  
       a light source connected to the actuator for emitting light onto the compact disc;  
       the method comprising:  
       measuring an error of focusing the light onto a track of the optical disc and generating a corresponding error signal;  
       providing a supplementary force in addition to the driving force to drive the sled so as to drive the actuator away from the non-linear region of the predetermined range if a magnitude of the error signal is greater than a predetermined value.  
     
     
       6. The method of  claim 5 , wherein the light source is capable of emitting light for writing data onto the compact disc.